The present invention relates generally to fuel burners, especially burners for waste fuel, such as waste plastic. Considerable research effort has been invested toward finding methods of converting waste plastics to usable fuels as a means of plastic recycling. Waste plastics are burned to generate heat, which may be used for water heating, industrial heat, or other purposes. Important considerations related to waste plastics as fuel sources are: maximizing energy by burning the solid fuel completely, minimizing heat losses to the environment, compactness of the burner, and minimizing soot and harmful gases emission.
Some existing waste fuel burners have multiple combustion chambers, which improve the completeness of the burning, but the combustion chambers are arranged one after another, therefore resulting in a long burner and significant heat losses due to the exposed outer surfaces.
Other existing waste fuel burners accumulate ash, soil, and sand during the burning process. These burners have to be periodically stopped for the removal of accumulated non-combustible material.
There is therefore a need for solid waste burners that minimize burner size and heat losses, while maximizing the completeness of fuel burning. The burner should also minimize soot and harmful gases emission, while reducing the accumulation of the non-combustible material inside the burner.